Insertion tongue

ABSTRACT

A plug-in tongue for a belt buckle of a seatbelt system. The tongue includes a plug-in section suitable for plugging into the belt buckle and with a belt-retaining section which has a slot for the passage and deflection of a seat belt. The plug-in tongue includes a metal plate which has a slot-shaped opening, and wherein at least one edge section of the metal plate, which edge section bounds the slot-shaped opening, is embedded into a plastics material. The edge section of the metal plate, which edge section bounds the slot-shaped opening, is bent out of the opening plane of the slot-shaped opening and has a hook-shaped cross section.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of International Patent Application Number PCT/DE2012/200070, filed Nov. 7, 2012, which was published in German as WO 2013/071927. The foregoing international application is incorporated by reference herein.

BACKGROUND

This application relates to an insertion tongue for a belt lock of a safety belt system.

Such an insertion tongue is known, for example, from the German Offenlegungsschrift DE 10 2007 043 338 A1. This insertion tongue has an insertion portion which is suitable for insertion in a belt lock of a safety belt system. Furthermore, the insertion tongue is provided with a belt retention portion which has a slot for introducing and redirecting a safety belt. The insertion tongue comprises a metal plate which has a slot-like opening. The position of the slot-like opening correlates to the slot of the insertion tongue, through which slot the safety belt can be guided for redirection. The edge of the metal plate delimiting the slot-like opening is embedded in a plastics material.

SUMMARY OF THE INVENTION

An object of the invention is to provide an insertion tongue which can be produced in a simple and cost-effective manner and which has a high level of mechanical stability.

Accordingly, there is provision for an insertion tongue to include an edge portion of a metal plate, which portion delimits a slot-like opening, to be bent out of an opening plane of the slot-like opening and to have a hook-like cross-section.

A significant advantage of the insertion tongue can be seen in that it is possible to produce therein a plastics coating which is at least approximately circular in cross-section in a very simple manner in the region of the slot-like opening. The plastics material can be applied in the region of the bent-over edge portion—as a result of the hook-like cross-section—with at least substantially the same thickness or wall thickness, whereby the production of the plastics coating is significantly improved, in particular in the case of the metal plate being covered with plastics material via injection molding. There is also less material waste and fewer sink marks, shrink holes or cracks are formed.

Another significant advantage of the insertion tongue is that the stability of the insertion tongue is very great. If the safety belt, for example, in the case of an accident, applies a pulling force to the insertion tongue, the plastics material is supported by the bent hook-like edge portion over a large surface-area. The tensile loading is consequently received both by the plastics material and by the edge portion which retains or supports the plastics material. As a result of the hook-like cross-section in the region of the edge portion of the metal plate, therefore, there are no corners or edges which could act on the plastics material in a wedge-like manner in the event of tensile loading and potentially destroy it. As a result of the shaping of the edge portion, deformations which can lead to an overload of the plastics material—brought about by the different levels of resilience of metal and plastics material—occur only in the case of very high forces and consequently significantly later than would be the case with conventional shaping of the metal plate.

A third significant advantage of the insertion tongue is that, in spite of the significant mechanical advantages mentioned, it can nonetheless be produced in a simple and cost-effective manner since the shaping of the bent edge portion of the metal plate can be achieved, for example, simply by means of punching, deep-drawing and bending of a metal sheet.

A fourth significant advantage of the insertion tongue is that, as a result of the shaping, that is to say, the hook-like cross-section, significant strengthening of the metal plate is achieved whereby, in the case of a high mechanical loading, for example, in the event of an accident, the danger of breaking or bending of the insertion tongue is significantly reduced. As a result of the high level of stability of the bent metal plate, it is further possible to use relatively thin metal sheets for the production thereof so that the production is more simple and cost-effective.

The bent edge portion is preferably the edge of the two opposing long edges of the slot-like opening that has the greater spacing from the insertion portion.

With regard to particularly great stability of the bent edge portion, it is considered to be advantageous for the edge portion to be bent through an angle of between 90° and 180°, in a particularly preferred manner through an angle between 90° and 135°.

The bent edge portion preferably has a deep-drawn portion which is adjoined by a bent portion. The hook-like cross-section of the bent edge portion thus preferably comprises two production steps, that is to say, a deep-drawing step, in which inter alia the deep-drawn portion is formed, and a bending step, in which the bent portion is formed.

The width of the hook opening of the bent edge portion, that is to say, the spacing between the front hook tip and the location of the edge portion opposite the hook tip is preferably at least as large as the thickness of the metal plate itself. Such a width of the hook opening makes it easier to embed the belt retention portion in the plastics material, in particular when the belt retention portion is coated with plastics material via injection molding.

The bent edge portion of the metal plate may, for example, have a cross-section which corresponds in terms of shape to the upper portion of a question mark.

It is considered to be particularly advantageous for the plastics material to form in the region of the bent edge portion a plastics layer which is at least partially curved, preferably in the form of a circular arc, in cross-section.

With regard to simple production, for example, in the case of coating with plastics material via injection molding, and with regard to maximum stability of the insertion tongue, it is considered to be advantageous for the outer side of the bent edge portion, which outer side faces the slot or the slot-like opening, to be partially curved, preferably curved in the form of a circular arc, in cross-section and for the curved outer side to be provided with a plastics layer which is curved in cross-section, preferably in the form of a circular arc. The layer thickness of the curved plastics layer which is preferably curved in the form of a circular arc is preferably between 0.7 and 3 mm.

The variation of the layer thickness is preferably less than 10% of the mean layer thickness of the curved plastics layer.

In order to prevent the safety belt from being able to slide through the slot of the insertion tongue in an unimpeded manner in the event of a vehicle accident or in the event of great tensile loading, it is considered to be advantageous for there to be formed, at the outer side on the plastics layer which is curved in cross-section, plastics material teeth which extend away from the bent edge portion of the metal plate.

In a particularly preferred manner, the teeth have a cross-section which inhibits sliding of the safety belt in one direction more than in the other direction. The cross-section of the teeth is preferably fin-like.

The tip of the teeth is preferably orientated in such a manner that, when the safety belt is positioned, the teeth inhibit the safety belt from sliding along from the shoulder region in the direction of the pelvic region.

In order to achieve optimum stability of the teeth, it is considered to be advantageous for the height of the teeth to be a maximum of 1.5 times the thickness of the curved plastics layer.

With regard to the orientation of the teeth relative to the orientation of the hook tip of the bent edge portion, it is considered to be advantageous for the tip of the teeth to be bent away in the same rotation direction as the hook tip of the bent edge portion. Alternatively, the tip of the teeth may be bent counter to the rotation direction of the hook tip of the bent edge portion.

In order to achieve an optimum angle between the insertion tongue and the safety belt, when the insertion tongue is freely suspended on the safety belt, it is considered to be advantageous for the belt retention portion to be bent out of the plane of the insertion portion and for the extent direction of the slot to have an angle with respect to the insertion portion between 10 and 19 degrees. The term “extent direction of the slot” is in this instance intended to be understood to be the direction in which the safety belt extends relative to the insertion tongue when the tongue is freely suspended on the safety belt which extends perpendicularly and which is retained in a tensioned state. The influence of a belt strap stopper on the resulting angle can be compensated for by means of a recess in the insertion tongue.

With regard to optimum stability of the insertion tongue and simple production, it is considered to be advantageous for the bent edge portion of the metal plate to be bent, in particular bent at right angles, out of the opening plane of the slot-like opening in the direction toward the plane of the insertion portion.

Alternatively, there may be provision for the bent edge portion of the metal plate to be bent, in particular bent at right angles, out of the opening plane of the slot-like opening, away from the plane of the insertion portion.

The bent edge portion of the metal plate is preferably embedded in a plastics strand, which has an outer contour which is partially curved in cross-section and which is in particular curved in the manner of a circular arc. The curved outer contour of the plastics strand is preferably orientated parallel or partially concentrically relative to the outer contour of the bent edge portion.

The curved outer contour of the plastics strand is preferably provided at least partially with teeth and partially with webs which have a smooth outer face. The function of the webs or the smooth outer face thereof is to make it easier to slide the safety belt over the plastics strand in the event of no or only a small tensile loading of the safety belt. However, if the tensile force of the safety belt is increased, the safety belt will come into contact with the teeth at the outer contour of the plastics strand and, depending on the sliding direction, be prevented from sliding to a greater or lesser extent by the teeth.

The webs are preferably guided radially around the outer contour of the plastics strand. In this instance, there may be provision for the webs to extend in an oblique manner around the outer contour of the plastics strand.

It is further considered to be advantageous for the insertion tongue to have an end portion which is separated from the insertion portion by the belt retention portion. The end portion and the insertion portion are preferably arranged parallel with each other.

As disclosed herein, an insertion tongue for a belt lock of a safety belt system is provided. The insertion tongue includes an insertion portion which is suitable for insertion in the belt lock and a belt retention portion which has a slot for introducing and redirecting a safety belt, the insertion tongue further comprising a metal plate having a slot-like opening.

There is provision for an edge portion of the metal plate, which edge portion delimits the slot-like opening, to be embedded in a plastics strand which has a partially curved outer contour in cross-section and for the outer contour of the plastics strand to be at least partially provided with teeth which inhibit sliding of the safety belt in one direction more than in the other direction. As already mentioned above, the safety belt is preferably intended to come into contact with the teeth on the outer contour of the plastics strand only in the event of a high tensile force, but not during normal operation; during normal use there should preferably not be produced any inhibition action, regardless of the direction. Inhibition should preferably occur only in critical situations, that is to say, under high loading and preferably in only one direction.

With regard to the advantages of this insertion tongue, reference may be made to the above statements.

The application further discloses a method for producing an insertion tongue. The method includes a provision for a metal plate to be punched, with a slot-like opening being formed, for the punched metal plate to be deep-drawn and for an edge portion of the metal plate, which edge portion delimits the slot-like opening, to be bent out of the opening plane of the slot-like opening in such a manner that the bent edge portion has a hook-like cross-section and for the bent edge portion to be embedded in a plastics material. The sequence of the deep-drawing step and the bending step can be freely selected.

With regard to the advantages of the method, reference may be made to the above statements with regard to the insertion tongue since the advantages of the method according substantially correspond to those of the insertion tongue.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with reference to embodiments; by way of example in the drawings:

FIGS. 1 to 8 show a first embodiment of an insertion tongue,

FIGS. 9 to 15 show a second embodiment of an insertion tongue, and

FIGS. 16 to 19 show a third embodiment of an insertion tongue.

DETAILED DESCRIPTION

In the Figures, for the sake of clarity, the same reference numerals are always used for components which are identical or comparable.

FIGS. 1 to 8 show a first embodiment of an insertion tongue 10. The insertion tongue 10 comprises an insertion portion 11 and a belt retention portion 12 which is provided with a slot 13.

The insertion portion 11 is provided with a recess 11 a through which a locking element of a belt lock can engage in order to retain the insertion tongue 10.

A safety belt 20 can be guided through the slot 13 in order to redirect it. FIG. 1 shows that the extent direction R of the slot 13 forms with respect to the insertion portion 11 an angle a which is preferably in the range between 10° and 19°.

FIG. 2 is a three-dimensional view of the insertion tongue 10 according to FIG. 1. The insertion portion 11, the belt retention portion 12 and the slot 13 can be seen. It is further possible to see a plastics strand 30 which delimits the long edge 13 a of the slot 13. Opposite the long edge 13 a is a long edge 13 b of the slot 13, which has a smaller spacing with respect to the insertion portion 11 than the other opposing long edge 13 a.

In FIG. 2, it can further be seen that the plastics strand 30 is at least partially circular in cross-section. The surface of the plastics strand 30 has four webs 40 which have a smooth surface so that the safety belt can slide over it. Between the webs 40 are portions having teeth 50 whose cross-section in a radial direction is at least substantially fin-like.

FIG. 3 is yet another view of the insertion tongue 10 according to FIG. 1. Here again, the plastics strand 30, the webs 40 and the teeth 50 can be clearly seen.

In FIG. 4, the insertion tongue 10 according to FIG. 1 is illustrated as a section. It can be seen that the insertion tongue 10 has a metal plate 60 having a slot-like opening 70 whose position correlates to the position of the slot 13 of the insertion tongue 10.

The inner edge portion 80 of the metal plate 60, which portion delimits the slot-like opening 70 in the region of the edge 13 a of the slot 13, has been bent out of the opening plane of the slot-like opening 70 so that a hook-like cross-section is formed. In the embodiment according to FIG. 4, the edge portion 80 is bent in the direction toward the plane of the insertion portion 11, that is to say, downward in the illustration according to FIG. 4.

FIG. 5 is a cut-away side view of the insertion tongue according to FIG. 1. It is possible to see the hook-like edge portion 80 which is embedded in a plastics material 90. The shaping of the bent edge portion 80 makes it possible for the outer side 81 of the edge portion 80 facing the slot or the slot-like opening 70 to be partially circular in cross-section. The plastics material 90 consequently forms on the outer side 81 of the bent edge portion 80 a plastics layer 91 which is consequently also partially circular in cross-section.

The plastics layer 91 which is circular in cross-section has a layer thickness which—without taking into account the teeth 50 formed on the plastics layer 90—is substantially constant. The variation in layer thickness of the plastics layer 91 is preferably less than 10% of the mean thickness of the plastics layer 91 in the region of the circular outer side 81 of the hook-like edge portion 80.

In FIG. 5, it is further possible to see the shaping of the teeth 50 in greater detail. It can be seen that the teeth 50 have a fin-like cross-section by means of which a preferred direction is defined. As a result of the fin-like cross-section, the teeth 50 inhibit sliding of the safety belt 20 according to FIG. 1 to differing degrees in accordance with the sliding direction. The orientation of the teeth 50 or the fin-like cross-section is preferably selected in such a manner that the teeth, when the safety belt is positioned (and in the event of high tensile force, see above) inhibit the sliding of the safety belt from the shoulder region of the vehicle occupant in the direction of the pelvic region of the vehicle occupant more than in the opposing direction.

In FIG. 5, it can further be seen that the height of the teeth 50 is approximately as large as the thickness of the plastics layer 91. The height of the teeth 50 is preferably in a range between 0.7 times and 1.5 times the thickness of the plastics layer 91. With such a thickness, the stability of the teeth 50 and the force transmission by the teeth 50 to the plastics layer 91 and consequently to the bent outer side 81 of the bent edge portion 80 is optimal.

Furthermore, FIG. 5 shows that the orientation of the fin-like teeth 50 corresponds to the bending direction of the bent edge portion 80. The bent edge portion 80 in FIG. 5 is thus bent upwards, which in terms of orientation corresponds to the fin orientation of the teeth 50.

FIG. 6 shows the shaping of the metal plate 60 of the insertion tongue 10 in greater detail. It is possible to see the bent edge portion 80 which is bent in the direction toward the plane of the insertion portion 11.

FIGS. 7 and 8 are other views of the metal plate 60 of the insertion tongue 10 according to FIG. 1. It can readily be seen in particular in FIG. 8 that the metal plate has an end portion 14 which is separated from the insertion portion 11 by means of the belt retention portion 12. The end portion 14 of the insertion tongue 10 and the insertion portion 11 are preferably located in mutually parallel planes or at a slight angle, preferably up to a maximum of from 10° to 15°.

FIGS. 9 to 15 show a metal plate 60 for a second embodiment for an insertion tongue 10. It can be seen that, in the embodiment according to FIGS. 9 to 15, the upper edge portion 80 of the metal plate 60 is bent or bent at right angles away from the plane of the insertion portion 11. The bending direction of the upper edge portion 80 is thus the reverse of the bending direction as provided for in the embodiment according to FIGS. 1 to 8.

In particular in FIGS. 10 and 13, the shaping of the upper edge portion 80 can be seen particularly clearly. It can thus be seen that the bent edge portion 80 has a deep-drawn portion 82 (cf. FIG. 11) which is adjoined by a bent portion 83. Therefore, the hook-like cross-section of the bent edge portion 80 is consequently formed by two production steps, that is to say, a deep-drawing step in which the deep-drawn portion 82 is formed, and a bending step, in which the bent portion 83 is formed.

The metal plate 60 according to FIGS. 9 to 15 can in further production steps be embedded in plastics material, as has already been explained with reference to FIGS. 1 to 8. In this instance, it is possible to form a plastics strand which is provided with webs and teeth and which embeds the upper edge portion 80 of the metal plate 60. In this regard, reference may be made to the above statements.

FIGS. 16 to 19 show a third embodiment for an insertion tongue 10, but in which the edge portion 80 is not bent in a hook-like manner. FIG. 16 is a three-dimensional illustration of the insertion tongue 10 in the cut-away state. It can be seen that the edge portion 80 of the metal plate 60 is embedded in a plastics strand 30 whose outer side has webs 40 (sliding webs) and teeth 50. The orientation of the webs 40 is different to that in the first embodiment according to FIGS. 1 to 8. It can thus be seen that the webs 40 are also guided radially, but in a slightly oblique manner around the outer side of the plastics strand 30.

FIGS. 17, 18 and 19 show the structure of the teeth 50 in greater detail. It can be seen that the teeth are fin-like in cross-section and thereby bring about a different inhibiting action in the event of the safety belt sliding past.

If, for example, in the illustration according to FIG. 19, the safety belt is pulled in the arrow direction P1 through the slot 13, the inhibiting action of the teeth 50 as a result of the fin shape will be very small. However, if the safety belt is pulled downward in the arrow direction P2 in FIG. 19, the fin-like teeth 50 will prevent the safety belt from sliding past in the event of significant tensile force, at least inhibit it significantly more than in the other direction. In order to ensure this operation, it is considered to be advantageous for the height difference between the height of the tooth tips and the height of the webs 40 (sliding webs) to be approximately from 0 to 0.6 mm.

The slot spacing which defines the spacing between the webs (sliding webs) 40 and the lower opposing edge of the area coated via injection molding preferably has such dimensions that free movement of the belt strap during normal use is ensured in both directions. The slot spacing preferably further has such dimensions that unintentional rotation of the belt strap in the slot is not possible either during normal use or during a critical situation.

The two outer sliding webs are preferably wider than the inner sliding webs. The two outer sliding webs are preferably so wide that, even in the event of oblique or other belt strap guiding, sliding is still ensured during normal use.

The position of the inner sliding webs is preferably selected in such a manner that, for example, in an asymmetrical manner, even in the event of curvature of the belt strap during normal use (for example, also during fastening or unfastening), there is no inhibition action.

The mechanical stability of the teeth is preferably sized by means of material selection and/or geometry in such a manner that the teeth fail before the belt strap fails.

The priority application, German Patent Application No. 10 2011 086 373.7, filed Nov. 15, 2011 is incorporated by referenced herein.

LIST OF REFERENCE NUMERALS

-   10 Insertion tongue -   11 Insertion portion -   11 a Recess -   12 Belt retention portion -   13 Slot -   13 a Edge -   13 b Edge -   14 End portion -   20 Safety belt -   30 Plastics strand -   40 Webs -   50 Teeth -   60 Metal plate -   70 Opening -   80 Edge portion -   81 Outer side -   82 Deep-drawn portion -   83 Bent portion -   90 Plastics material -   91 Plastics layer -   R Extent direction -   P1 Arrow direction -   P2 Arrow direction 

What is claimed is:
 1. An insertion tongue for a belt lock of a safety belt system, comprising: an insertion portion which is suitable for insertion in the belt lock and a belt retention portion which has a slot for introducing and redirecting a safety belt, wherein the insertion tongue comprises a metal plate which has a slot-like opening, and wherein at least one edge portion of the metal plate, which portion delimits the slot-like opening, is embedded in a plastics material, wherein the edge portion of the metal plate, which portion delimits the slot-like opening, is bent out of the opening plane of the slot-like opening and has a hook-like cross-section.
 2. The insertion tongue as claimed in claim 1, wherein the outer side of the bent edge portion, which side faces the slot-like opening is partially curved in cross-section and the curved outer side is provided with a plastics layer which is curved in cross-section.
 3. The insertion tongue as claimed in claim 2, wherein at the outer side on the curved plastics layer there are formed plastics teeth which extend away from the bent edge portion of the metal plate.
 4. The insertion tongue as claimed in claim 3, wherein the teeth have a fin-like cross-section which inhibits sliding of the safety belt in one direction more than in the other direction.
 5. The insertion tongue as claimed in claim 1, wherein the belt retention portion is bent out of the plane of the insertion portion and the extent direction of the slot has an angle with respect to the insertion portion between 10 and 19 degrees.
 6. The insertion tongue as claimed in claim 1, wherein the bent edge portion of the metal plate is bent, in particular bent at right angles, out of the opening plane of the slot-like opening in the direction toward the plane of the insertion portion.
 7. The insertion tongue as claimed in claim 1, wherein the bent edge portion of the metal plate is bent, in particular bent at right angles, out of the opening plane of the slot-like opening, away from the plane of the insertion portion.
 8. The insertion tongue as claimed in claim 1, wherein the bent edge portion of the metal plate is embedded in a plastics strand which has an outer contour which is partially curved in cross-section, wherein the curved outer contour is preferably parallel with the outer contour of the bent edge portion.
 9. The insertion tongue as claimed in claim 8, wherein the curved outer contour of the plastics strand is partially provided with teeth and partially with webs which have a smooth outer face.
 10. An insertion tongue for a belt lock of a safety belt system, comprising: an insertion portion which is suitable for insertion in the belt lock and a belt retention portion which has a slot for introducing and redirecting a safety belt, wherein the insertion tongue comprises a metal plate having a slot-like opening, wherein an edge portion of the metal plate, which edge portion delimits the slot-like opening, is embedded in a plastics strand which has a partially curved outer contour in cross-section, and the outer contour of the plastics strand is at least partially provided with teeth which inhibit sliding of the safety belt in one direction more than in the other direction.
 11. A method for producing an insertion tongue as claimed in claim 1, comprising the steps of: punching a metal plate with a slot-like opening being formed, the punched metal plate is deep-drawn and an edge portion of the metal plate, which edge portion delimits the slot-like opening, is bent out of the opening plane of the slot-like opening in such a manner that the bent edge portion has a hook-like cross-section, and embedding the bent edge portion in a plastics material. 